


Life will change through improvement

by Aviisalittlefreak



Series: What lies beneath the soul [1]
Category: Undertale (Video Game)
Genre: Other
Language: English
Status: In-Progress
Published: 2020-09-29
Updated: 2020-12-23
Packaged: 2021-03-08 00:14:10
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 5
Words: 3,935
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26716570
Author URL: https://archiveofourown.org/users/Aviisalittlefreak/pseuds/Aviisalittlefreak
Summary: Taking place after a Pacifist Run and after an incident where he met other version of himself, Sans was peacfully living with Red, Fell Sans, and Parashade, Fresh Sans. But what happens when a Sans and a Papyrus that they've never met shows up in their lives?
Series: What lies beneath the soul [1]
Series URL: https://archiveofourown.org/series/1945903
Kudos: 3





	1. Welcome!!!!

Hey guys! I'm Jackson! It's a pleasure yo be able to post this here, but i hope you guys have fun reading this!!! Love you all!!💜💜


	2. What lies in store for today?

**Notes for the Chapter:**

> Hey guys! Im hoping that this'll be something you guys like as a story! Im not to good with writing, but 8 wanted to do something for fun!!

3rd person POV

It was a warm but quite windy day as a trio of skelton monsters walked down the street, having a lighthearted and seemingly funny conversation. The three skeletons shared a name. Sans. However, they each had their own nicknames. Classic, Red, and Parashade. Parashade went by Fresh most of the time but he prefered Parashade, or just Para.

The three skeletons continued their conversation with a happy vibe around them. However, after a bit, the three were startled by a loud thud near by. This caused Para to stop. "Wait minute, dudes. What was that?" The other two shrugged in confused. Wanting to know what had happened, out of curiosity more then anything, Para went to check what that had been. He nearly knocked his own shades off at the sight of a much smaller skeleton laying on the ground with large cracks all over his skull. His clothes were torn and he seemed to be... bleeding? "Oh jeez, what in the name of..." The shaded skeleton picked the smaller skele up and immediately went back over to the others who were with him. At the sight of the newer skeleton, Red got defensive until he noticed their sleeping state and how badly hurt he seemed. In unspoken agreement, the three immediately took the small skele back to Classic's house. "Red, because you've had to deal with a cracked skull, can you perhaps take care of bandaging the little dude while me and Classic look for some clothes for him to wear?" 

"What makes you think i cant handle patching him up?" Red snapped a bit, causing the other two skeletons to laugh before heading to find clothes for the little skele. 

"Hey Red, remember that one time Blueberry tried to make clothes for you and they were way to small? Why don't we put those on the little guy thats on the couch?" Para grinned, holding up a green jacket with bright blue fluff as the hood, a pair of brown pants, and a pair of grey boots. This caused Red to roll the single light in his eyesocket, seemingly not giving a shit.

"Sure. Whatever. I dont care, as long as you dont put him in my room." He growled. After a while, Red had finished with the bandaging and the others had put the new clothes on him, the three had taken to waiting for the smaller skeleton to wake up. They didnt have to wait long. However, the small skele started crying and panicking immediately after waking up. "Oh son of a bitch..." Red grumbled out. "Great, he fuckin cries. As if we don't already have enough of that around here already." This resulted in him getting a light smack from Classic, who had taken to gently trying to comfort the smaller skele.

"Hey.. Hey... it's gonna be okay.. dont worry.. we aren't gonna hurt ya." Classic said, giving a small comforting grin instead of his normal lazy one. It seemed to work in his favor, as the smaller skele grabbed onto Classic's arm and nuzzled him. "So you must also be a Sans, huh..? What's your nickname?" He asked gently. The smaller skele looked up at Classic with two toxic green, glowing lights in his eyesockets. He had green tears leaking from his eyesockets as well. 

"I'm.... I-i'm Monoxide...." the small skeleton said wiyh a small stutter. He was shaking as he looked around. "Wh-where am I....?" This cause Classic to gently chuckle and gently sit beside Monoxide.

"You're in my home. My friend Para over there found ya behind a tree." As Classic explained, the mentioned Fresh gave a small wave. However at the friendly gesture, Monoxide flinched away and nuzzled into Classic's side. This caused Para and Classic to look at each other. Red just rolled his eye light at the small skeleton. They all seemed to be thinking the same thing. 'This is gonna change things....'

But they arent prepared for just how much this will in fact change.


	3. Things can only get steanger from here, huh?

**Notes for the Chapter:**

> Hello to whoever is reading!!
> 
> Please please do not skip this note!!
> 
> I'm just gonna say that there are some triggering themes in this story, such as different forms of a*use and other things! 
> 
> Warnings will be in the beginning of the chapters, in the notes! 
> 
> If you are uncomfortable with that kind of thing, please do not continue to read!

As the four skeletons sat in an akward silence, Red was glaring at the smallest of them. After a while, Para spoke up. "So, where are you from?" He smiled gently at Monoxide, causing Monoxide to gently smile back at him.

"I-i'm... I'm from an AU called P-periodictale..." Monoxide explained gently."I-it's lovely there, i-if you can ignore some of the other monsters there....." He seemed to be warming up to the other skeletons in the room, as his eyelights had went to white dots.

"Oh, so you're from a not really well known AU then." Classic says with a small hum of interest. Red rolls his eyelights as he gets up amd storms up the stairs. After that, a door slamming is heard through the house. The sound caused Monoxide to jump and fall off the couch. He yelped in surprise.

"Oh shoot! You okay there, little broski!?" Para asks, leaning down to help the smaller skele up. Monoxide gives a gentle nod in response as he shakes a bit

"Y-yeah... I'm.. I'm o-okay..." he smiled a bit, taking Para's hand. The larger skele helps monoxide to his feet, grinning.

"Well, as long as you're okay, dude!" Para grins at him with a gentle expression. Para removes his shades, to the surprise of Classic. Monoxide looks up at Para's eyes, curiously.

"Y-you're eyes are pr-pretty.... Th-they remind me of my friend Detroit...! H-he has eyes like yours...! H-he even has a similar jacket.....!" Monoxide said, seemingly a bit more excitable then a few moments ago. His green eyelights flickered back into his eyes happily. He giggled a bit. This caused Para to look a bit confused.

"Your friend has eyes like mine? That's cool!" He chuckled a bit while very gently patting the smaller skele on the bandaged skull. Monoxide perked up at the gentle pat, seeming to let his smile grow larger. 

Classic looked at the two, before looking at the opening door. He chuckled as his brother walked in, setting down bags and holding somone on his back.... "Brother, I'm ho-- oh, are you and the oyher yous done with the walk?" He asked, surprisingly quieting down his voice by a lot. 

"Uh.. yeah, bro... who's... who's that on your back?" Classic asked, with a confused and ckncerned expression. This caused the tall, scarf wearing skeleton to gently move his slull to look at the form he was holding.

"Oh..! I found this other me beside one of the dumpsters at the store, and I couldnt just leave him so I brought him home with me...! I found a nevklace beside him that said Antidote on it..! Perhaps that's his name?" Bean, Classic Pap, said with a gentle curisoity. He set the skeleton down on the couch beside Monoxide.

Monoxide's eyesockets went blank as he tensed up a bit. "Wh-what did you say his n-name possibly was....?" The small skele asked scared of both Bean and the Papyrus that was just set down. 

"I said his name could possibly be Antidote..! I dont understand why it would be, but he looks really sweet...!" Bean said as he looked over. "Is... is there something wrong, other version of my brother? You look scared." Monoxide visibly flinched away at those words.

"N-nope...! J-just uhm... u-uh... w-well...." Monoxide stumbled over his words, visibly panicked. He looked anywhere but at Bean. His nervousness was clear as day as Classic sat beside Monoxide.

"Bud... do you and your bro have issues with each other?" The question from Classic caused Monoxide to shrink away from the larger skele. Classic let out a gently sigh, as did Para. They looked at each other, worried that had been the case.

".... what does he--" before Para could continue to speak, Monoxide interrupted him.

"H-he hits me... he yells at me... he hurts me.. he always says that its my fault... H-he... he hurts others too...." Monoxide was shaking as Bean and Classic looked surprised. Para's eyes had went blank. Monoxide looked away from them as his body shook. His eyesockets welled up with green liquid as he let out a shuttery noise.

They were all suddenly startled by the Papyrus on the couch stirring awake and letting out a small groan. He looked smaller then Bean, as he gently pushed hismelf up."Wh-what the...?" He groaned as he rubbed his skull."Wh-where....?" He looked up a bit. At the sight of Monoxide, the Papyrus flung himself backwards into a wall."Pl-platinum...?" The action caused Monoxide to fall off the couch once more.

At the same time the papyrus had said the name Platinum, Monoxide had spoken as well. "A-arsenic....?" This caused the two skeletons to give each other confused looks.

The interaction was causing quite a lot of confusion between the other skeletons. Red, who had just walked down the stairs, let out a grumble as he went back to his room and slammed the door.

In an attempted to break the confusion, Classic asked the Papyrus two questions. " Whats your name? And could you tell us where you're from?"

The Papyrus looked up and nodded gently. Fixing his bandages on his skull, he let out a shuttery noise.

"M-my name is Antidote, or Antivenom.... I-i'm from Periodicswap..."

**Notes for the Chapter:**

> Chapter two is complete! I hope you guys enjoyed this chapter! As ive stated beforez this story isnt supposed to be a professional thing! 
> 
> Characters and nicknames
> 
> Original Sans- Classic
> 
> Original Papyrus- Bean
> 
> Fresh Sans- Red
> 
> Fresh Sans- Fresh/Parashade/Para
> 
> Periodictale Sans- Monoxide
> 
> Periodicswap Papyrus- Antidote/Antivenom 
> 
> Undertale, along with Sans and Papyrus, belongs to Toby Fox 
> 
> Fell Sans was created by the person who created Underfell
> 
> Fresh Sans was created by Crayon Queen
> 
> Periodictale and Periodicswap are AUs created by me.


	4. Relationships can change and grow

**Summary for the Chapter:**

> It seems that Monoxide amd Red's relatiosnhip is starting to get better!! Red at least shows some kindness to him!!

_It's been about a month since Monoxide and Antidote had moved in. Another Papyrus had moved in as well but they don't know what AU he's from. He goes by Crown._

_They've all been doing their best to get better. It seems that they've helped each other with that. It was revealed to Monoxide that Classic and Para are indeed a couple. The concept of them being together confused him at first but he didn't really say anything. Antidote has seemed to form a bond with Crown and Crown has seemed to take an older brother role over the smaller Papyrus._

_Monoxide gets along well with Para and Classic, even going out on walks with them when he gets the chance to._

_But Red and Monoxide still haven't had the best relationship. It seens like Red has no intentioms of being kind towards the smaller skeleton. In reality, Red just doesnt know how to talk to him. But maybe.. just maybe their relationship will get a bit more friendly with time, right?_

* * *

At the moment, Monoxide and Antidote were curled together on the couch with Crown while Para sat on the floor, Classic sat in Para's lap, and Red was sitting in a chair. The skeletons were silent and peaceful, just enjoying hanging out together. Antidote was smiling as they all started to chat, enjoying their time together. They all seemed at ease, even Red. Crown was asleep, having his head laying in Monoxide's lap. Monoxide smiled gently and pet the Papyrus' skull gently. He thought he heard a small chuckle from Red but when he looked over, Red was just glaring at him. He sighed gently and looked away from him. Antidote hummed out as he started to chat with Classic and Para. Red had gotten up and grabbed a bottle of water before just sitting back down. He.. didnt even do anything with it and just held it. Hos eyelights flicked to look at Monoxide for a second and for a moment, the smaller skeleton swore he saw Red blushing a dark crimson color.

After a bit, Antidote and Crown got up to go to their own rooms and rest. This left Monoxide on the couch alone. He kinda huffed as he sat there. "Can i sit down there with you guys...?" He asked Para and Classic. Before eituer of the two could say yes, Monoxide had been picked up by Red and placed into the fell's lap. This cause Monoxide to become startled. Red grumbled and held the smaller skeleton in his lap.

"Don't get used to this. I just don't wanna hear you whining about not sitting with someone." He growled out gently. This caused Monoxide to give a small smile to the larger skeleton. He cuddled into Red's lap, causing the fell to let out a surprised grunt in response. He kept his arms around Monoxide and muttered something to himself. Classic and Para were both trying to not laugh at the scene in front of them. Red growled out a warning towards them which pushed them over the edge, so they started laughing. Red angrily growled. "What!? What's so funny!?" Monoxide squeaked and kinda hid his skull in the blue fluff of his jacket. In the moment that the smaller skeleton couldn't see Red's expression, the larger skeleton softened it. Para and Classic loved seeing Red being so gentle with someone. Monoxide then suddenly turned and buried his skull in the fluff of Red's jacket. He mumbled something but none of them quite caught it. Red blushed darkly and stuttered a bit, due to the way that Monoxide was now sitting had him slightly straddling the larger skeleton. "I- wh- huh--- I-- uhhhh-----" Classic snickered as he looked at Red, grinning widely.

"I see you're warming up to him, Red." Classic and Para snickered a bit as Red blushed brighter. He glared at them and held Monoxide.

"Shut up! I just dont want him whining about not having someone to sit with!" Red snapped at them, blushing dark enough to look as if he was covered in blood. Monoxide just laughed gently at this and tried to get up, only to be pulled back down by Red, who grumbled to himself. "Don't fuckin move..." he grumbled, causing Monoxide to squeak in surprise but keep himself planted in the larger skeletons lap.

And thats how the day had went. Now it was night time and Red was asleep with Monoxide asleep on his lap. Classic and Para had gone to their rooms. The three Papyrus' of the household were with some friends for the night, just havibg the times of their lives.

A small noise in the kitchen sounded as a portal opened and two skeletons walked out. The first one had a very large knife in his hand. The other... he.. The aura he gave off was.. negative.. purely negative... The first one stood guard at the portal, silently muttering to hismelf in annoyance. The one with the negative aura silently made his way to the living room and picked up Monoxide without a sound. Without waking any of them, the skeleton grinned widely before making his way back to the kitchen and through the portal just holding Monoxide close to his chest. The first one had followed. "Why the hell do we need him in the first place??" He questioned, only to get a glare from the other. Once they were on the other side of the portal, it closed. Only then did Monoxide start to stir a bit. "H-huh...? What's.... going on....?"when he looked up, Monoxide froze. His white pinprick eyelights exstiguished at the sight of Nightmare holding him and Cross standing at Nightmare's side. The two much larger skeletons looked at Monoxide with two different expressions. Crosa seemed like he didnt really care and Nightmare... Nightmare was absolutely terrifying, just smiling with a sort of crazed emotion very clear in his demeanor. Monoxide was frozen in fear as Nightmare spoke.

**"Welcome home, my new little brother~"**

And the others slept, unaware in that moment that Monoxide had been taken. 

.... That's not gonna be a fun thing to discover in the morning, is it?


	5. Thinga really aren't gonna be good for a while....

**Notes for the Chapter:**

> I made this chapter while liseting to Diary of Jane so it's a bit angsty.  
> Not the best but eh.  
> I like it!  
> Im proud of myself, y'know!?

The others had freaked out when they woke up, only to find Monoxide missing. Red teleported around different AUs to try and find him but never did. Para and Classic looked around the house and neighborhood. They didn't find him either.

And they weren't going to.

Monoxide was sitting on the floor while looking up at Nightmare, who was sitting on his throne and 'happily' grinning at the smaller of the two. Monoxide was confused. He didnt understand what Nightmare's intentions were and that scared him. Nightmare suddenly reached out with one of his tentacles and grabbed Monoxide, pulling him into his lap and hugging him **"ah, it's so nice to finally have you with me, my new little brother~"** Monoxide whimpered a bit at Nightmare's behaviour. Monoxide tried to puch himself out of Nightmare's arms, scared half to death. His eyesockets were empty, devoid of his eyelights. Nightmare wrapped his other tentacles around the smaller skele, holding him close **. "Don't you dare try and get away from me. Let me hold you."** He hissed a bit at first but then just relaxed his voice. Nigthmare kept the smaller skele on his lap for a while longer before letting him go. Monoxide immediately pushed himself as far away from Nightmare as possible. Nightmare watched him silently, a grin forming.

"I... I-i don't understand... wh-what do you mean by that...?" Monoxide whimpered out as he teared up a bit. The sight of the tears caused Nightmare to immediately pull Monoxide back into his lap so he could wipe the tears off the smaller skeletons skull..

 **"What do you mean, brother? What don't you understand?"** Nightmaee asked, seemingly concerned. **"Do you mean about me calling you my brother? Well, It's because you remind me so much of how my brother was before he was killed and a new guardian took his place. But you remind me so much of my dear brother and how kind he was. I just can't let that be ruined, now can I?"** Nightmare hugged Monoxide to his ribs and hummed, stroking the smaller skeleton's bandaged skull. **"But don't worry, its all gonna be okay. You won't be able to leave me. For safety reasons of course. But you'll stay in the castle and I even set up a room for you right beside mine. You'll never be hurt and anyone that tries will face... consequences."** Nightmare hummed. He felt the smaller skeleton in his arms shivering and scared for his own life despite Nightmare saying he wouldn't be hurt. Monoxide let out small whimpers of fear, causing Nightmare to forwn and cup his skull gently. **"Brother, whats wrong? Are you alri--"**

"I-i want you to take me home..." Monoxide said all of a sudden. "I.. i don't want to be here.... y-you can't just force me to stay here.... stop calling m-me your brother.... I'm not your br-brother...." Those words cause Nightmare to go silent as he stared at Monoxide. All of a sudden Nightmare burst into laughter, holding the smaller skeleton even tighter against him.

 **"Aw! It's cute how you think you have a choice here! You're staying with me and that's final! You are my brother now and for the rest of the time you have in this life! It's not you're decision! There's nothong to be upset about! I'll take care of you, you'll be protected, you'll finally have a brother who actually cares for you!"** Nightmare yelled, making Monoxide look at him. The yelling had caused Monoxide to start shaking harder, making him want to get farther away from Nightmare. 

"Wh...what is wromg with you...!? Don't you see how wr-wrong this is....!?" Monoxide yelled at him, eyesockets brimming with tears. The next thing the small skeleton knew was that he was on the ground, holding his cheek in pain where Nightmare had just slapped him. 

**"Dont you DARE ever yell at me again!! I am your brother! I'm trying to PROTECT you, and I won't have you leaving me!! Do you understand!?"** Nightmare yelled at Monoxide, grabbing his by the collar of his jacket. The small Sans looked up at Nightmare with fear, tears streaming down with cheekbones. Monoxide noddded, more tears falling. He shuddered when Nightmare kissed the top of his skull. **"I'm sorry brother. Im sorry that I yelled at you. But you have to understand. I'm just trying to protect you. You get that, right?"** Nightmare said gently as he cupped Monoxide's skull in his hands. Monoxide hesitantly nodded as Nightmare began to let go. He gave a smile to Monoxide then told him where his room was. Monoxide immideatly ran off yo his room, holding his cheekbone gently. He threw himself onto the bed and cried, eyesockets screwed shut. He hoped so hard that the others were looking for him.

And they were. The others were searching as hard as they possibly could. 

Red seemed to be the ome who was the most worried, which surprised the other two. Para and Classic called for Monixide and Red yelled his name. They searched everywhere that they possibly could. They didn't want to get anyone like Error or Ink involved but they would if absolutely necessary. 

They had all just gotten back to the house and were worriedly looking at each other in silence. 

All of a sudden Red had growled and yelled out. "I shoulda fuckin known!!!" He was wiping something off of the kitchen floor. "You guys recognize this shit?" Red asked, holding of his hand that was covered in a certain goop. Para and Classic immideatly tensed up.

"You don't think Nightmare took him, did you?" Classic asked, worried as all living hell. Yes, Monoxide had gotten a bit stronger during the time he's lived with them but he still wasn't the strongest guy ever. This worried the hell out of every single one of the Sans'. They gave each other knowing looks before Para teleported away to go talk to Error and Ink. Red and assic sat in a tense silence, giving each other knowing looks. The two knew exactly how bad Nightmare could be if others got in his way or tried to take what the nagative guardian claimed as 'his'. But they weren't worried about themselves. They were worried for Monoxide. "This... this isnt good, Red....."

"Ya think I don't know that, dickwad? I'm fuckin terrified about what could happen to him!! He was in MY arms and Nightmare took him! I failed to keep him safe!!!" Red rmuelled all of a sudden, bright red tears streaming down his cheekbones. He punched a wall, causing Classic to give him a worried look.

"Red, its the fault if all of us... not just you.... I... he... he was righ there and none of us woke up to see him sbeing taken.. none of us knew he had been taken. We're all to blame for this." Classic grabbed Red's shoulder as he spoke, pulling him into a hug. "Believe me.... its hard... i know... but we can and we will get him back. I know we can. Now stop punching the wall. If you keep punching it, I'll have to rebuild it again. And I don't wanna have to do that." Classic joked, punching Red's shoulder a bit. This caused the edgy akeleton to laugh a bit and grin gently.

"I... thanks, Classic..... I'm... I needed that.... " Red sighed a bit. "Well... what should we do...?" He asked. The question caused Classic to shrug. 

"Guess we gotta wait for Para to get back to us about if Error and Ink will help us get Monoxide back." He said as he shrugged. The two skeletons sar on the couch and silently sighed. Red just looked at the tv then turned it on as Classic picked up a book. That didn't stop the overwhelming feeling of worry that was plaguing them but it was a nice distraction. Now they just had to wait to see if Error and Ink would actually help.


End file.
